A classical representation of an extended body over barriers of height greater than the energy of the incident body is shown to have many features in common with quantum tunneling as the center-of-mass literally goes through the barrier. It is even classically possible to penetrate any finite barrier with a body of arbitrarily low energy if the body is sufficiently long.A distribution of body lengths around the de Broglie wavelength leads to reasonable agreement with the quantum transmission coefficient.

Performance and economic evaluation results are presented for steam injected combustion turbine systems. The steam injected gas turbine plant shows a potential for low capital cost and high efficiency for sites where water consumption is not a deterrent. Steam produced in a heat recovery steam generator is injected into the gas turbine combustor section to the extent of 0.155 pounds steam per pound of air flow. Water consumption is estimated to be 2.5 pounds per kWh (1.13 kg/hWh). When burning distillate fuel at 2200°F (1204°C), the potential efficiency is 40 percent as compared to 38 percent for a simple cycle gas turbine, and the specific output per pound of air flow is increased by 30 percent. The estimated capital cost per kilowatt is 3 percent greater than that for the simple cycle gas turbine.

A continuing technology development program initiated by General Electric (GE) in the early 1960s and joined by the Electric Power Research Institute (EPRI) in 1974 is successfully resolving potential barrier problems in the development of water cooled turbines. Early work by GE Corporate Research and Development demonstrated the feasibility of closed circuit, pressurized water-cooling of stationary nozzles (vanes), and of open circuit, unpressurized water-cooling of rotating buckets (blades). A small-scale turbine was designed, fabricated, and operated at a gas temperature of 2850 F (1565 C) at 16 atm, with surface metal temperatures less than 1000 F (540 C). Early results from the EPRI sponsored Water-Cooled Gas Turbine Development Programs were presented at the 1978 Gas Turbine Conference (Report #ASME 78-GT-72). This paper reports more recent results, obtained between mid-1977 and mid-1978. Significant progress has been made in a number of areas: (a) water-cooled nozzle and bucket design and fabrication, (b) corrosion kinetics model verification and testing, (c) partially filled internal channel bucket heat transfer testing, and (d) stationary to rotating water transfer and collection testing. Results to date are encouraging with regard to the application of water-cooled turbine components to achieve improved reliability and fuels flexibility at increased turbine firing temperatures.

The objective of this project is to evolve design guidelines based on considerations of deposition and corrosion, for future operation of large stationary combustion turbines for electric power generation. The primary emphasis of the investigation is to establish the operating blade surface temperature, considering all aspects of deposition and corrosion, for a range of fuels including residual oil and coal-derived liquids. The design guidelines that will evolve from this program will provide a data base to determine the trade-offs between metal temperature, performance, maintenance and reliability. There is, at present, some operating and lab experience that indicates the possibility of serious deposition problems as turbine inlet temperature (TlT) increases, and as the differential between TlT and blade surface temperature increases. The concern regarding corrosion effects is centered on two considerations: a) Will metal surface temperature continue to govern the corrosion process as TlT increases, and b) Will present-day additives be effective at higher in-let temperatures and cycle pressures? Evaluation of the initial test results is presented.

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